Improvement in saw-grinding machines



'PATENT-OFFICE `EMANUEL ANDREWS,'oFvviLLrAMS1?oRT, PENNSYLVANIA.

IM PROVEMENTAIN SAW-GRI N DING MACHINES.

` Specification forming part of Letters 'Patent No. 81,126, dated August18, 1868'.

To all whom it may concern Y Be it known that I, EMANUEL ANDREWS, ofWilliamsport, VLycoming county, Pennsylfvania, have invented an ImprovedSaw-Grinding Machine; vvand I do -herebydeclare the following to be afull, clear, andexact description ofthe same, reference being had to theaccompanying drawing, 'and to the letters of reference marked thereon. p

My'invention consists of certain mechanism, fullydescribed'he'reinafter, for grinding saw- .blades'and reducing them toaproper tapering form. y

In order to enable others skilledin the art to makeand use my invention,I will now proceed to 'describe its construction and operation." v v Onreference to the accompanying drawing, which forms a part'of thisspecification, Figure l is a vertical sectionof my 'improvedsaw-grinding machine, Fig. 2 an inverted plan vlew, Flg. 3 a transversesection, and Figs. 4

'and 5 parts "of themachine drawn to)l an enpins adapted to4 holes inthebase-plate, or'

being otherwise so guided that it can have a limited vertical movementonly, the opposite sides a a of the frame beingV beveled at the upperedge, so as to form V-shapedways for the'sliding bed F.

To the base-plate A are secured two rods, e and e', on each of which ishung a lever, G, each lever consisting, in the present instance, of twobars united at one end, as seen in Fig. 2.

On the outer ends of the short arms of these levers rests the frame E,as shown in Fig. l, and on the ends of the long arms of both levers restprojections on a third lever, H, which has its fulcrum at t', Fig. 3,and the outer end of which is furnished with an adjustable weight, h.The long arm of a fourth lever, I, Fig. 3, which has its fulcrum at k ona cross-bar of the base A, is connected by a link, j, to the lever H,the short arm of the said lever I being formed to receive the foot )barD.

of the attendant, and being limited, as regards its upward movement, bya'screw, l'inpassing through a bracket, n, secured to the exterior ofthe base A.

K is a spind-leturningin bearings-p @which are arranged to slide invertical guides formed in the standards B and'B., each bearing beingconnected-by two bolts, q q, Fig. 4, to a plate,

s, which is also arranged to slide in the said guides, `and throughwhich passes a screwspindle, L, both screw-spindles turning in and beingconined to the cross-bar D, and having bevel-Wheels t gearing intosimilar wheels w on a transverse shaft, M, which-is arranged to turnin-suitable boxes N Nf on the said'cro'ss- (See'Fi'g. 3.)

A screw-spindle, P, having threads adapted `to similarthreads in aplate, secured by bolts y y to one of the bearings p, (see Figs.y 2 and3,) is so coupled to one end of the spindle *K that thelatter can bemoved to or fro transversely by operating the hand-wheel on the end ofythe said'screw-spindle.

' A grindstone, Q, isr secured to thespindle K between thestandards'B-and'B, and one end of the'said spindle is provided with apulley, It, for receiving a driving-belt.

' 0n one edge of the sliding bed F is a rack, T, into the teeth of whichgear the pinions 2 2, on transverse shafts 3 3, 'each shaft beingarranged to turn in bearings 4 4, which slide in guides 5 5, which are'secured to the opposite edges of the sliding bed F, and which are actedon by weighted levers 6.

Each shaft has a roller, y, the arrangement 0f the two rollers inrespect to the grindstone being best observed on reference to Fig. l.

A screw-shaft, 7, is arranged to turn in the opposite ends of the oblongframe E, its threads being adapted to those of a nut, 8, which isconined to a projection on the under side of the bed F. One end of thescrew-shaft is furnished with a bevel-wheel, gearing into a similarwheel on a transverse shaft, 9, which turns in the frame E, near one endof the same, this shaft being furnished with suitable pulleys forreceiving driving-straps, and with suitable appliances by which anautomatic reversal of the movement of the shaft 9, and consequently ofthe screw-shaft 7 may beeffected, as in ordinary planing-machines.

Operation: The saw-blade to be ground is adjusted to the sliding bed F,between which, however, and the blade, intervenes a thin plate, w', Fig.3, of a shape conforming or nearly conforming to that of the said blade.It should be understood that-in this machine there is no necessity forappliances for securing the blade and its plate, fr', simply placingboth on their proper positions on the bed beneath the rollers y y beingall that is neces-- sary, after which the bed may be released, so thatthe full force of the weighted lever H and levers G and G' may beexerted to raise the bed and cause the blade to bear against the stone.

Arapid rotary motion is now imparted to the grindstone Q, and a slowtraversing movement, first in one direction and then in the other, isimparted to the bed. Owing to the rack T and' pinions 2, the movement ofthe rollers y g/ is controlledby that of the traversing bed, and theserollers are of such a diame- 'ter that their circumferences will moveat-precisely the same speed as the bed', hence the rollers afford aneffective medium for confining the blade and its plate w to the bedwithout exerting any drag which might tend to displace or strain eitherblade or plate. f

As the bed approachesl the limit of either its backward or forwardmovement, the blade and its plate will pass from beneath one or other ofthe rollers, but the remaining roller is amply sufficient to so confinethe blade that it cannot be disturbed by the action of the stone.

An attendant can, at any time during the operation of the machine, alterthe lateral position of the stone by turning the screw l?, or can raiseor lower the stone by turning the shaft M. Should it be necessary at anytime to discontinue the operation of the stone on the blade, thevattendant can in a moment lower the frame E with its bed by placing hisfoot on the lever I, and undue reduction of the blade may always beavoided by a proper adjustment of the screw m, which limits the upwardmovement of the bed.

It will be seen, on reference to Fig. 4, that the bearings p p of thegrindstone-shaft K may be separately adjusted vertically by the bolts qq, and that the angle of the lsaid shaft in respect to the surface ofthe bed can 'consequently be altered at pleasure. In view of thisadjustability, and of the fact that the plate w, on which the bladerests, may be made of any required taper, it will be evident to thosefamiliar with machinery of this class that any taper desired may beimparted to the blade, not only laterally, but also from end to end, ordiagonally.

Without confining myself to the precise construction and arrangement ofthe several parts, as herein described, I claim as my invention anddesire to secure by Letters Patent v l. The combination of the slidingbed F, grindstone Q, and two rollers, 4 4, when the latter are gearedtoand their circumferences are caused to traverse at the same speed as thebed, substantially as described, for the purpose specified.

2.' The combination of the traversing bed, the frame E, and the systemof levers herein described, or the equivalent to the same, whereby ayielding upward pressure `is applied to elevate the said frame and bed.

3. The combination of the said traversing bed, the frame E, the systemof levers herein described, or their equivalents, and the set.- screw m,or its equivalent, whereby the extent of the upward movement of the saidbed may be limited without preventing the bed from yielding, whennecessary.

4. fihe combination of the traversing bed, the grindstone-spindle, andits bearings, when the latter admit of separate vertical adjustment, asdescribed.

5. The combination ofthe grindstone-spindl e, the operating-screw P, andthe devices or their equivalents connected therewith, for the purposeofimparting a lateral motion to the said grindstone.

In testimony ywhereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EMANUEL ANDREWS.

Witnesses:

- H. HowsoN,

GHARLEs HowsoN.

